The conversion of lactic acid to high-molecularweight PLA is achieved by two routes. Cargill uses a solvent-free process and a novel distillation process to produce a range of polymers.3 The essential novelty of the process lies in the ability to
go from lactic acid to a low-molecular-weight polylactic acid, followed by controlled depolymerisation to produce the cyclic dimer, commonly referred to as lactide.